In the furniture industry and for laminate floor panels, decorative papers are used for visible surfaces of wood or fiberboard panels. For this purpose, a printed paper web is impregnated with synthetic resins such as urea resin or melamine and optionally provided with abrasion-resistant particles such as corundum, for example, in order to impart certain characteristics to the web. The web is subsequently dried and cooled. Unprinted paper, i.e. paper without decorative elements, is also used in part. An apparatus and method for making an impregnated web (impregnates) is known from the prior art and described, for example, in DE 20 2007 011 437 and DE 197 10 549.
Manufacturers of furniture and/or laminates are taking measures to drastically reduce their warehoused stock. This means that they order relatively small quantities of a given decorative element that is to be delivered on a certain date.
The impregnation and coating of paper webs is very elaborate when using the known methods and systems. In particular, the production of rejects during start-up and shut-down of the devices, as well as the effort involved, are very high. To wit, the web must first be threaded by hand into an impregnation station and optionally through impregnation baths. The web is impregnated and discarded until an adequate impregnation outcome is achieved. Only then is the web cut, and the new leading end of the web extends from an intake device through a dryer and a cooler. Rejects also occur downstream of these devices initially until a satisfactory final web quality has been achieved. It is only then that the production of usable impregnate is begun, and it is cut into sheets or spooled. Where necessary, the desired impregnation/coating agents must be gathered and exchanged for those already present in the system. Relatively large quantities of about 800 l of resin are required for this. The setup time for preparation takes more than an hour. All things considered, the costs of labor and rejects during startup and shutdown are therefore high. For this reason, impregnation operations are not able to economically produce small quantities of impregnated goods and are forced to reject such orders or fill them at a loss. The speed of the web during threading and drawing-in are much slower than the production speed.
One approach to solving the above-described problem is described in DE 10 2009 021 164. There, it is proposed that an intake device for a web be moved generally along a horizontal plane from a region upstream of an impregnation station to downstream of a cooler.
In terms of the invention, the term “impregnation station” refers to the application of resin to a web, independently of the type of application used, for example dipping, spraying, or coating, and of the function, whether the resin is being applied for the purpose of impregnation or coating (for example of a pretreated web). The term “impregnation” is used generically.